A policeman on the street looking at a driving license, an inspector looking at a business permit, an admissions officer looking at a diploma or grade transcript, a security guard looking at an ID badge, a potential buyer looking at a land title, and countless others who are presented with “original” or “official” documents must often ask themselves: “How do I know this document is authentic and unaltered?” This issue of document authentication has existed at least since ancient Mesopotamians rolled engraved cylinders onto clay tablets. Ever since, European monarchs, Asian emperors, popes and officials have been pressing signet rings into melted wax or rolling jade yinzhang onto parchments and scrolls. Indeed, in many cultures throughout history, possession of the official document seal was itself seen as proof of legitimacy and ruling power. Even today, there is often a requirement for notarization or obtaining an apostille for many types of documents. Now that documents may be created, altered, and copied with only a few keystrokes and clicks of a mouse, the question of provable authenticity is as important as ever.
One disadvantage of existing document verification schemes is that they are often inconvenient at best, frequently impractical, and sometimes expensive. For example, it may not always be convenient to have to find a notarius publicus for domestic legalization of a document, or to submit the document to the appropriate Foreign Ministry agency responsible for overseeing apostilles according to the Hague Apostille Convention. At a less international level, it may be impractical to have to return to one's university to get a certified copy of past diplomas or grade transcripts. In some circumstances, it may in practice be nearly impossible to verify the authenticity of a presented document—the police officer, for example, will in general have no reasonable way to check that driving licenses presented at a routine traffic stop do not have fake photographs or altered birthdates. Other expensive methods of prevention of physical documents forgery include special printers, papers, holograms, watermarking, etc., such as are used to create passports and paper money. These methods make it more difficult or expensive to forge, but still do not offer instant or even convenient verification of the source of the document without correspondingly specialized technology and training.
Even the supposedly high-tech world of inventions and patents still sometimes functions in the era of ribbons, seals, and embossing tools: patent applicants who file applications in their home countries normally are required to get physical, officially certified “priority documents” from their respective national patent offices and send these to foreign firms for submission to foreign patent authorities in order to establish the right of priority.
Another disadvantage is that the use of physical seals still does not rule out the possibility of alterations or outright counterfeiting. This is especially true where official documents are easily forged, officials may be bought off or at least difficult to contact for confirmation, or of questionable reliability themselves. In the United States, for example, there are often minimal requirements to become a “notary public”, who may often be in a distant state. On the other side of the globe, even now it is common for Chinese businesses to have their official seal, which they use to “chop” company documents. Such seals, however, are often made in small shops and can be easily reproduced. Of course, with the advent of high-resolution color laser printers, the ease of creating fully believable counterfeits of official documents and even seals has increased dramatically. These circumstances simply raise the question of trust to a higher level, that is: “How can I trust that this official seal proves authenticity of this document?”
Still another drawback of many existing document verification systems is that they presuppose immediate access to technology that may simply not be available in many real-life situations—despite the seeming ubiquity of portable computers, they are not always available. For example, a policeman on foot may want to be able to check that the photo on an ID document actually corresponds to the person the ID document supposedly belongs to.
What is needed is therefore some system and method for verifying documents that is convenient, easily accessible, and more trustworthy and believable than existing solutions.